Well, nobody ever faulted ACA routes for being too direct. I did this route last summer. You do have to go south to duck under Lake Superior, but it seems like the ACA sends you farther south than necessary.
If you ask Google for a route from Grand Rapids, MN to Escanaba, MI, it comes up with a 358 mile route. The ACA route between these two cities is 601 miles. Yes, the ACA route is a lot longer, but I would never suggest using an ACA route to somebody who is in a hurry to get somewhere. I'd rather meet Donn Olson at the Adventure Cyclists Bunkhouse in Dalbo, see the world's largest black bear in Glidden and ride on Wisconsin's Rustic Roads than see Duluth.
Note, you're going to think the ACA sends you too far out of the way again in the lower peninsula of Michigan. I sometimes wondered why I spent three days going southwest when I was trying to get to the northeast.